It’s quite simple to teach most dogs to use a “dog doorbell“ which can either ring chime or send a notification to your phone depending on the specific brand/model. It’s not really any different than the dog learning to scratch at the door when they want to go out, most of them pick it up very quickly. 
This is a typical one that does not integrate with SmartThings.
https://www.amazon.com/Paws2Go-Training-Device-Mobile-Alerts/dp/B07JL53J36
But if you want ST integration, You can also just use any button that works with your smartthings system that the dog is able to press with either nose or paw. There’s an FAQ discussing some possible options:
This approach is usually simpler than trying to find a the device that the dog wears. 